Prepare a wood or charcoal grill for direct-heat grilling, or use a grill pan on top of the stove.,Trim the tops of the green garlic where the leaves begin to branch out.,Peel an outside layer of the stalks and slice thinly on the bias.,Or very thinly slice the garlic cloves.,Set aside.,Cut the lettuce in quarters lengthwise and brush all over with olive oil; season with salt and pepper.,Place the lettuce cut-side down on the grill and cook until it has darkish grill marks, 2 to 3 minutes.,Flip lettuce quarters to the other cut side and grill for another couple of minutes, then grill on the leafy side briefly.,Remove from grill when done.,______,When the liquid is at a roaring boil, add the peas and garlic and cook, tasting often for seasoning and adding more water as needed, 3 to 8 minutes, or until the peas are just tender.,Add the mint leaves and cook 1 minute.,The goal is to have just enough water at the end of the cooking time to emulsify with the oil and thicken slightly.,To serve, spread the lettuce on a platter and pour the peas and their minty, garlicky juices over it.,Serve with grilled chicken, roast duck or by itself.